OSIRIS-REx: Chemical and structural analysis of asteroidal material returned from C-type asteroid Bennu.

这个提议是我们在JAXAs隼鸟2号任务框架内对来自龙宫的小行星样本进行非常成功的研究的后续。小行星样本研究的延伸嵌入在样本返回任务OSIRIS-REx（起源，光谱解释，资源识别，安全，风化层探测器）（NASA）中，其任务目标是调查碳质c级近地小行星Bennu。在提议的项目中，我们将在OSIRIS-REx任务的框架下，在矿物学和岩石学工作组（MAPWG）初步调查小组中应用同步辐射XRF和TEM分析。OSIRIS-REx任务的两个最主要目标是：1)“返回并分析原始碳质小行星风化层样本，其数量足以研究其组成矿物和有机物质的性质、历史和分布”；2)“绘制原始碳质小行星的全球属性、化学和矿物学，以表征其地质和动态历史，并为返回的样本提供背景”。其目标是获得关于类地行星和小天体之间的关系、地球的起源和地球的有机物质和水的来源的新的基本信息。碳质小行星被认为自太阳系形成以来变化最小，可以让我们了解这些物质是在最早的行星形成时代就存在于类地行星区域，还是在晚阶段的轰击中被带到地球。样本材料是在2020年直接从小行星本努的表面收集的，目前正由OSIRIS-REx航天器带回地球，该航天器将于2023年9月24日抵达。抵达后，这些直接收获的小行星材料将被运送到约翰逊航天中心（JSC）的OSIRIS-REx管理设施，进行称重、分类和管理。然后，其中一些材料将分发给主要调查小组，即由专家小组组成的国际跨学科小组，以便进行具体的目标分析。作为OSIRIS-REx任务的指定专家团队之一，我们将参与该项目的初始分析阶段，并将成为首批接收本努材料的团队之一。在我们对Bennu材料的研究中，我们将获得化学、矿物学和岩石学数据，这些数据将有助于破译Bennu的水、热和冲击历史，应用两种独立的分析方法，即同步加速器- xrf和透射电镜。

This proposal is a follow-up of our very successful study of asteroidal samples from Ryugu in the framework of JAXAs Hayabusa2 mission. The elongation of the study of asteroidal samples is embedded within the sample return mission OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) (NASA), whose mission target is the investigation of the carbonaceous C-class near-Earth asteroid Bennu. In the proposed project we will work in the framework of the OSIRIS-REx mission in the mineralogy and petrology working group (MAPWG) preliminary investigation team applying synchrotron radiation XRF and TEM analyses. The two most primary objectives of the OSIRIS-REx mission are: 1) to “return and analyze a sample of pristine carbonaceous asteroid regolith in an amount sufficient to study the nature, history, and distribution of its constituent minerals and organic material”; and 2) to “map the global properties, chemistry, and mineralogy of a primitive carbonaceous asteroid to characterize its geologic and dynamic history and provide context for the returned samples”. The goal is to acquire new and fundamental information about the relationship between the terrestrial planets and the small-body populations, the origins of the Earth and the source of the Earth’s organic materials and water. Thought to be minimally altered since the formation of the Solar System, carbonaceous asteroids may provide insight into whether these materials were present in the terrestrial planet region during the earliest planet formation era, or delivered to the Earth by a late phase of bombardment. Sample material was directly collected from the asteroid Bennu´s surface in 2020 and is currently being carried back to Earth on board the OSIRIS-REx spacecraft, due to arrive on the 24th September 2023. Upon arrival, this directly harvested asteroidal material will be transported to the OSIRIS-REx curation facility at the Johnson Space Centre (JSC), weighed, sorted and curated. Some of the material will then be distributed to the primary investigating teams, an international and interdisciplinary group of expert subteams, for specific targeted analysis. As one of the designated expert teams of the OSIRIS-REx mission, we will be involved in the initial analysis stage of the project and will be one of the first teams to receive some of the Bennu material. In our investigation of the Bennu material, we will obtain chemical, mineralogical and petrological data that will help decipher the hydrous, thermal and shock history of Bennu, with the application of two separate analytical methods, namely synchrotron-XRF and TEM.